LINQ-related error when using simple CSharpCodeProvider in ASP.NET

Question

I've created a very simple custom compiler:

public class SimpleCompiler : CSharpCodeProvider
{
    public SimpleCompiler() : base()
    {
        File.AppendText("d:\foo.txt","bar");
    }
}

In my web.config file, I copied/pasted existing configuration to declare this new compiler.

<compiler language="c#;cs;csharp" extension=".cs" type="XXX.SimpleCompiler, XXX" warningLevel="4">
    <providerOption name="CompilerVersion" value="v3.5"/>
    <providerOption name="WarnAsError" value="false"/>
</compiler>

But I get errors when accessing user controls with code like:

<asp:Label runat="server" ID="Label3">
    <%# 
         string.Join("<br/>",((ReadOnlyCollection<AAA>)Eval("ListOfAs")).Select(x => x.Name).ToArray())                                 
    %>
 </asp:Label>

It fails on > of <AAA>. Something should be missing somewhere (using?), but it builds fine with standard compiler Microsoft.CSharp.CSharpCodeProvider.

Error message is:

Compiler Error Message: CS1525: Invalid expression term '>'

Update: It seems to be related to LINQ. It fails on all pages with LINQ in control code. However System.Core.dll is included in Web.config.

Update2: I was able to reproduce it in a new Web Application project.

Add a new class:

namespace WebApplication1
{
    public class SimpleCompiler : CSharpCodeProvider
    {
        private void Log(string message)
        {
            File.AppendAllText("d:\\foo.txt", DateTime.Now.Ticks+Environment.NewLine);
        } 
   }

}

Update web.config

<system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="WebApplication1.SimpleCompiler, WebApplication1">
          <providerOption name="CompilerVersion" value="v3.5"/>
          <providerOption name="WarnAsError" value="false"/>
        </compiler>
    </compilers>
</system.codedom>

change Default.aspx to:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebApplication1._Default" %>
<%@ Import Namespace="System.Linq" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
    <head runat="server"></head>
    <body>
        <form id="form1" runat="server">
        <div>
            <%
                int x = (new int[] { 1, 2, 3, 4, 5 }).Where(z => z > 2).Count();
                this.Response.Write(x);
            %>
        </div>
        </form>
    </body>
</html>

If I update project to 4.0, it works. But I can't do that in other one.

Can you demonstrate this *without* using ASP.NET, e.g. from a simple console app? — Jon Skeet, Nov 19 '12 at 17:27
Code is working fine if I use "default" compiler thus I'm pretty sure `x => x` is OK. I'm using .NET 3.5. But I can't figure out how to test it outside Asp.NET: most of pages build fine, and only such code is broken. — Francois, Nov 19 '12 at 20:05
I have tested this with a VS2010 web project, and it works fine for me (my compiler class resides in a C# in the web project). Can you post a repro project somewhere? — Simon Mourier, Nov 20 '12 at 08:29
I'm afraid I can't (company project). For now my compiler class is in another project. I'll try your way. — Francois, Nov 20 '12 at 08:39

score 0 · Answer 1 · answered Nov 21 '12 at 02:14

0

Try add to Web.config:

<pages>
   <namespaces>
      <add namespace="System.Linq" />
   </namespaces>
</pages>

and

<compilation>
    <assemblies>
        <add assembly="System.Core" />
    </assemblies>
</compilation>

answered Nov 21 '12 at 02:14

abatishchev

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@FrancoisB: And absolutely the same code is being compiled fine with default C# compiler, correct? – abatishchev Nov 21 '12 at 17:40
Right. Only Linq expressions fail to build. – Francois Nov 21 '12 at 19:43

LINQ-related error when using simple CSharpCodeProvider in ASP.NET

1 Answers1